NAME

ha.cf - Configuration file for the Heartbeat cluster messaging layer

DESCRIPTION

/etc/ha.d/ha.cf is read by heartbeat(8) upon node start-up. It lists
the communication facilities enabled between nodes, enables or disables
certain features, and optionally lists the cluster nodes by host name.
This file can safely be made world readable, but should be writable
only by root.

GLOBALDIRECTIVES

Some directives in ha.cf are global in nature. The order of these
global options is important in configuring the ha.cf file, since each
directive is interpreted as it is encountered in ha.cf.
These directives are use_logd and udpport. It is recommended that these
be placed first in the ha.cf file when they are entered.
Other directives in this category are baud, logfacility, logfile, and
debugfile, but those directives are deprecated and should no longer be
used.

SUPPORTEDDIRECTIVES

The following directives are supported in ha.cf (listed here in
alphabetical order):
apiauth
This directive specifies what users and/or groups are allowed to
connect to a specific API group name. The syntax is simple:
apiauth apigroupname [uid=uid1,uid2 ...] [gid=gid1,gid2 ...]
You can specify either a uid list, or a gid list, or both. However
you must specify either a uid list or a gid list. If you include
both a uid list and a gid list, then a process is authorized to
connect to that API group if if it is either in the uid-list or it
is in the gid-list.
The API group name default has special meaning. If it is specified,
it will be used for authorizing clients without any API group name,
and all client groups not identified by any other apiauth
directive.
Unless you specify otherwise in the ha.cf file, certain services
will be provided default authorizations as follows:
Table1.Defaultserviceauthorizations
+--------------+-----------------+
|Service | Defaultapiauth |
+--------------+-----------------+
|ipfail | uid=hacluster |
+--------------+-----------------+
|ccm | gid=haclient |
+--------------+-----------------+
|ping | gid=haclient |
+--------------+-----------------+
|cl_status | gid=haclient |
+--------------+-----------------+
|lha-snmpagent | uid=root |
+--------------+-----------------+
|crmd | uid=hacluster |
+--------------+-----------------+
autojoin
The autojoin directive enables nodes to join automatically just by
communicating with the cluster, hence not requiring node directives
in the ha.cf file. Since our communication is normally strongly
authenticated, only nodes which know the cluster key can join
(automatically or otherwise).
The values you can give for the autojoin directive have the
following meanings:
o none: disables automatic joining.
o other: allows nodes other than ourself who are not listed in
ha.cf to join automatically. In other words, our node has to be
listed in ha.cf, but other nodes do not.
o any: allows any node to join automatically without being listed
in ha.cf, even the current node.
Note that the set of nodes currently considered part of the cluster
is kept in the hostcache file. With autojoin enabled, the node
directive is no longer authoritative - the hostcache file is.
bcast
The bcast directive is used to configure which interfaces Heartbeat
sends UDP broadcast traffic on. More than one interface can be
specified on the line. The udpport directive is used to configure
which port is used for these broadcast communications if the
udpport directive is specified before the bcast directive,
otherwise the default port will be used. A couple of sample bcast
lines are shown below.
bcast eth0 eth1 # on Linux systems
bcast le0 # for Solaris systems
Note
Broadcast links are not supported in Pacemaker clusters on BSD
systems.
compression
The compression directive sets which compression method will be
used when a message is big and compression is needed.
It could be either zlib or bz2, depending on whether you have the
corresponding library in the system. You can check
/usr/lib/heartbeat/plugins/HBcompress to see what compression
module is available.
If this directive is not set, there will be no compression.
compression_threshold
The compression_threshold directive sets the threshold to compress
a message, e.g. if the threshold is 1, then any message with size
greater than 1 KB will be compressed. The default is 2 (KB). This
directive only makes sense if you have set the compression
directive.
conn_logd_time
The conn_logd_time directive specifies the time Heartbeat will
reconnect to the logging daemon if the connection between Heartbeat
and the logging daemon is broken. The conn_logd_time is specified
according to the Heartbeat time syntax, for example:
conn_logd_time 60 #60 seconds
The default is 60 seconds.
Note
Heartbeat will not automatically reconnect to the logging
daemon. It only tries to reconnect when it needs to log a
message and conn_logd_time have passed since the last attempt
to connect.
coredumps
The coredumps directive tells Heartbeat to do things to enable
making core dumps - should it need to dump core.
The allowed values are true and false.
crm
historical, for Cluster Resource Manager, now an alias to pacemakerpacemaker
Enables the Pacemaker cluster manager. For historical reasons, the
default for this option is off; however, it should always be set to
respawn.
When set to respawn, the directive automatically implies:
apiauth stonithd uid=root
apiauth stonithd-ng uid=root
apiauth attrd uid=hacluster
apiauth crmd uid=hacluster
apiauth cib uid=hacluster
respawn hacluster ccm
respawn hacluster cib
respawn hacluster attrd
respawn root stonithd
respawn root lrmd
respawn hacluster crmd
deadtime
The deadtime directive is used to specify how quickly Heartbeat
should decide that a node in a cluster is dead. Setting this value
too low will cause the system to falsely declare itself dead.
Setting it too high will delay takeover after the failure of a node
in the cluster.
debug
The debug directive is used to set the level of debugging in effect
in the system. Production systems should have their debug level set
to zero (i.e., turned off). This is the default. Legal values of
the debug option are between 0-255. The most useful values are
between 0 (off) and 3. Setting the debug level greater than 1 can
have an adverse effect on the size of your log files, and on the
system's ability to send heartbeats at rapid rates, thus affecting
the cluster reliability.
The debug level of the system can also be specified on the command
line using the -d option. Additionally, the debug level of the
system can be dynamically changed by sending the heartbeat process
SIGUSR1 and SIGUSR2 signals. SIGUSR1 raises the debug level, and
SIGUSR2 lowers it.
hbgenmethod time|file
The hbgenmethod directive specifies how Heartbeat should compute
its current generation number for communications. This is a
specialized and obscure directive, used mainly in firewalls which
have no local disk, and other devices which do not have a method of
storing data persistently across reboots. It defaults to storing
the Heartbeat generations in a file. Generation numbers are used by
Heartbeat for replay attack protection.
Warning
If one specifies the time method, there are certain possible
cases where troubles can arise. If a machine restarts Heartbeat
and its local time of day clock is less than or equal to than
the value of the time of day clock when Heartbeat last started,
then that node will be unable to join the cluster.
initdead
The initdead parameter is used to set the time that it takes to
declare a cluster node dead when Heartbeat is first started. This
parameter generally needs to be set to a higher value, because
experience suggests that it sometimes takes operating systems many
seconds for their communication systems before they operate
correctly. initdead is specified according to the Heartbeat time
syntax. A sample initdead value is shown below:
initdead 30
In some switched network environments, switches engage in a
spanning tree algorithm whenever a NIC connects to a port. This can
take a long time to complete, and it is only necessary if the NIC
being connected is another switch. If this is the case, you may be
able to configure certain NICs as not being switches and shrink the
connection delay significantly. If not, you'll need to raise
initdead to make this problem go away.
If this is set too low, you'll see one node declare the other as
dead.
keepalive
The keepalive directive sets the interval between heartbeat
packets. It is specified according to the Heartbeat time syntax.
logfacility
The logfacility is used to tell Heartbeat which syslog logging
facility it should use for logging its messages.
The possible values for logfacility vary by operating system, but
some of the most common ones are {auth, authpriv, daemon, syslog,
user, local0, local1, local2, local3, local4, local5, local6,
local7}.
A sample logfacility directive is shown below:
logfacility local7
If you want to disable logging to syslog:
logfacility none
mcast
The mcast directive is used to configure a multicast communication
path. The syntax of an mcast directive is:
mcast dev mcast-group udp-port ttl 0
o dev - IP device to send/rcv heartbeats on
o mcast-group - multicast group to join (class D multicast
address 224.0.0.0 - 239.255.255.255). For most Heartbeat uses,
the first byte should be 239.
o port - UDP port to sendto/rcvfrom (set this to the same value
as udpport)
o ttl - the ttl value for outbound heartbeats. This affects how
far the multicast packet will propagate. (0-255). Set to 1 for
the current subnet. Must be greater than zero.
A sample mcast directive is shown below:
mcast eth0 239.0.0.1 694 1 0
mcast6
The mcast6 directive is to configure an IPv6 multicast
communication path. The syntax of an mcast directive is:
mcast6 [device] [mcast6 group] [port] [mcast6 hops] [mcast6 loop]
For example, using link-local scope with some "transient" group:
mcast6 eth0 ff12::1:2:3:4 694 1 0
o device - IP device to send/rcv heartbeats on
o mcast6 group - multicast group to join. Refer to
http://tools.ietf.org/html/rfc3513#section-2.7 for valid and
reserved IPv6 multicast addresses.
For most heartbeat uses, addresses should be taken from:
ff12::/16
Plausibility checking code during config file parsing will
reject some, but will probably not be able to catch all
unsuitable addresses. Please understand the IPv6 multicast
addressing scheme first.
Donotusereservedorwellknownmulticastaddresses.
You likely would seriously confuse a lot of network
devices.
o port - UDP port to sendto/rcvfrom
o mcast6 hops - affects how far the multicast packet will
propagate (sockopt: IPV6_MULTICAST_HOPS). (0-4). Set to 1 for
link-local.
o loop - sockopt IPV6_MULTICAST_LOOP; always set to 0
msgfmt classic|netstring
The msgfmt directive specifies the format Heartbeat uses in wire.
o classic - Heartbeat will convert a message into a string and
transmit in wire. Binary values are converted with a base64
library.
o netstring - Binary messages will be transmitted directly. This
is more efficient since it avoids conversion between string and
binary values.
When in doubt, leave the default (classic).
node
The node directive tells what machines are in the cluster. The
syntax of the node directive is simple:
node nodename1 nodename2 ...
Node names in the directive must match the "uname -n" of that
machine.
You can declare multiple node names in one directive. You can also
use the directive multiple times. Normally every node in the
cluster must be listed in the ha.cf file, including the current
node, unless the autojoin directive is enabled.
The node directive is not completely authoritative with regard to
nodes heartbeat will communicate with. If a node has ever been
added in the past, it will tend to remain in the hostcache file
more until it's manually removed.
realtime on|off
The realtime directive specifies whether or not Heartbeat should
try and take advantage of the operating system's realtime
scheduling features. When enabled, Heartbeat will lock itself into
memory, and raise its priority to a realtime priority (as set by
the rtprio directive). This feature is mainly used for debugging
various kinds of loops which might otherwise cripple the system and
impair debugging them.
The default is on.
rtprio
The rtprio directive is used to specify the priority at which
Heartbeat runs. It does not need to be specified unless other
realtime priority programs are also running on the system. The
minimum and maximum values for this field can be determined from
the sched_get_priority_min(SCHED_FIFO) and
sched_get_priority_max(SCHED_FIFO) calls respectively. The default
value for rtprio is halfway between the minimum and maximum values.
A sample rtprio directive is shown below:
rtprio 5
ucast
The ucast directive configures Heartbeat to communicate over a UDP
unicast communications link. The udpport directive is used to
configure which port is used for these unicast communications if
the udpport directive is specified before the ucast directive,
otherwise the default port will be used.
The general syntax of a ucast directive is:
ucast dev peer-ip-address
Where dev is the device to use when talking to the peer, and
peer-ip-address is the IP address we will send packets to.
A sample ucast directive is shown below:
ucast eth0 10.10.10.133
This directive will cause us to send packets to 10.10.10.133 over
interface eth0.
Note that ucast directives which go to the local machine are
effectively ignored. This allows the ha.cf directives on all
machines to be identical.
udpport
The udpport directive specifies which port Heartbeat will use for
its UDP intra-cluster communication. There are two common reasons
for overriding this value: there are multiple bcast clusters on the
same subnet, or this port is already in use in accordance with some
locally-established policy.
The default value for this parameter is the the port ha-cluster in
/etc/services (if present), or 694 if port ha-cluster is not in
/etc/services. 694 is the IANA registered port number for Heartbeat
(a.k.a. ha-cluster).
A sample udpport directive is shown below.
udpport 694
You have to configure udpport (in ha.cf) before you configure ucast
or bcast, if not heartbeat will use the default port (694).
Note
Due to a specification error in the syntax of the mcast
directive, this directive does not apply to mcast
communications.
use_logd on|off
The use_logd directive specifies whether Heartbeat logs its
messages through logging daemon or not.
If the logging daemon is used, all log messages will be sent
through IPC to the logging daemon, which then writes them into log
files. In case the logging daemon dies (for whatever reason), a
warning message will be logged and all messages will be written to
log files directly.
If the logging daemon is used, logfile/debugfile/logfacility in
this file are not meaningful any longer. You should check the
config file for logging daemon (the default is /etc/logd.cf).
If use_logd is not used, all log messages will be written to log
files directly.
The logging daemon is started/stopped in heartbeat script.
Setting use_logd to "on" is recommended.
uuidfrom
In the normal case, heartbeat generates a UUID for each node in the
system as a way of uniquely identifying a node - even if it should
change nodenames. This UUID is typically stored in the file
/var/lib/heartbeat/hb_uuid.
For certain kinds of installations (those booting from CDs or other
read-only media), it is impossible for heartbeat to save a
generated to disk as it normally does. In these cases, one can use
the uuidfrom directive to instruct heartbeat to use the nodename as
though it were a UUID, by specifying uuidfrom nodename.
All possible legal uuidfrom directives are shown below.
uuidfrom file
uuidfrom nodename
warntime
The warntime directive is used to specify how quickly Heartbeat
should issue a "late heartbeat" warning.
The warntime value is specified according to the
HeartbeatTimeSyntax. A sample warntime specification is shown
below.
warntime 10 # 10 seconds
The warntime directive is important for tuning deadtime

DEPRECATEDDIRECTIVES

The following directives are interpreted by the configuration file
parser for historical reasons, but should be considered deprecated and
should no longer be used.
auto_failback
In legacy Heartbeat clusters, the auto_failback option would
determine whether a resource would automatically fail back to its
"primary" node, or remain on whatever node is serving it until that
node fails, or an administrator intervenes. The possible values for
auto_failback were:
o on - enable automatic failbacks
o off - disable automatic failback
o legacy - enable automatic failbacks in systems where all nodes
in the cluster do not yet support the auto_failback option.
This option has been replaced the configurable failback policies in
Pacemaker, and should no longer be used.
baud
The baud directive is used to set the speed for serial
communications. Any of the following speeds can be specified,
provided they are supported by your operating system: 9600, 19200,
38400, 57600, 115200, 230400, 460800. The default speed is 19200.
This option is obsolete as serial links should not be used in
Pacemaker clusters.
deadping
The deadping directive is used to specify how quickly Heartbeat
should decide that a ping node in a cluster is dead. Setting this
value too low will cause the system to falsely declare the ping
node dead. Setting it too high will delay detection of
communication failure.
This feature has been replaced by the more flexible pingd resource
agent in Pacemaker, and should no longer be used.
debugfile
The debugfile directive specifies the file Heartbeat will write
debug messages to.
This directive is ignored when use_logd is specified. Enabling
use_logd is the recommended approach.
hbaping
Hbaping directives are given to declare fiber channel devices as
ping nodes.
This directive was never fully supported in Heartbeat (requiring
manual modifications to the code base) and should not be used.
hopfudge
The hopfudge directive controls how many nodes a packet can be
forwarded through before it is thrown away in the worst case.
However, the hopfudge value is added to the number of nodes in the
system. It defaults to 1.
This option applies to serial links only, which are deprecated.
logfile
The logfile directive configures a log file. All non-debug messages
from Heartbeat will go into this file.
This directive is ignored when use_logd is specified. Enabling
use_logd is the recommended approach.
ping
Ping directives are given to declare ping nodes to Heartbeat. The
syntax of the ping directive is simple:
ping ip-address ...
Each IP address listed in a ping directive is considered to be
independent. That is, connectivity to each node is considered to be
equally important.
In order to declare that a group of nodes are equally qualified for
a particular function, and that the presence of any of them
indicates successful communication, use the ping_group directive.
This feature has been replaced by the more flexible pingd resource
agent in Pacemaker, and should no longer be used.
ping_group
Ping group directives are given to declare a group ping node to
Heartbeat. syntax of the ping_group directive is as follows:
ping_group group-name ip-address ...
Each IP address listed in a ping_group directive is considered to
be related, and connectivity to any one node is considered to be
connectivity to the group.
A ping group is considered by Heartbeat to be a single cluster node
(group-name). The ability to communicate with any of the group
members means that the group-name member is reachable. This is
useful when (for example) two different routers may be used to
contact the internet, depending on which is up, or when finding an
appropriate reliable single ping node is difficult.
This feature has been replaced by the more flexible pingd resource
agent in Pacemaker, and should no longer be used.
respawn
The respawn directive is used to specify a program to run and
monitor while it runs. If this program exits with anything other
than exit code 100, it will be automatically restarted. The first
parameter is the user id to run the program under, and the second
parameter is the program to run. Subsequent parameters will be
given to the program as arguments.
This functionality was primarily designed for the legacy ipfail
program, which has been replaced by the more flexible pingd
resource agent in Pacemaker. Thus, this directive should no longer
be used, except when it is implicitly generated by pacemakeryes.
serial
The serial directive tells Heartbeat to use the specified serial
port(s) for its communication. The parameters to the serial
directive are the names of tty devices suitable for opening without
waiting for carrier first. On Linux, those ports are typically
named /dev/ttySX.
A few sample serial directives are shown below:
serial /dev/ttyS0 /dev/ttyS1 # Linux
serial /dev/cuaa0 # FreeBSD
serial /dev/cua/a # Solaris
The baud directive is used to configure the baud rate for the
port(s) if the baud directive is specified before the serial
directive, otherwise the default baud rate will be used.
Using this option is strongly discouraged in Pacemaker clusters, as
its CIB updates can easily hit practical message size limits for
serial links, with undefined results.
stonith
The stonith directive is used to configure Heartbeat's legacy
STONITH configuration. It assumes you're going to put in a STONITH
configuration file on each machine in the cluster to configure the
(single) STONITH device that this node will use to reset the other
node in the cluster.
This functionality has been replaced by STONITH agents in
Pacemaker.
stonith_host
The stonith_host directive is used to configure Heartbeat's
(release 1 only), STONITH configuration. With this directive, you
put all the STONITH configuration information for the devices in
your cluster in the ha.cf file, rather than in a separate file.
This functionality has been replaced by STONITH agents in
Pacemaker.
traditional_compression on|off
This directive enables traditional compression. It is highly
recommended that this be set to off (the default); otherwise
heartbeat performance can be significantly negatively impacted.
watchdog
The watchdog directive configures Heartbeat to use a watchdog
device. In some circumstances, a watchdog device can be used in
place of a STONITH device. In any case, it is a reasonable thing to
configure if you don't have a STONITH device, or if you wish, in
addition to your STONITH device.
It is the purpose of a watchdog device to shut the machine down if
Heartbeat does not hear its own heartbeats as often as it thinks it
should. This keeps things like scheduler bugs from becoming
split-brain configurations.
The general syntax of a watchdog directive is:
watchdog watchdog-device-name
A sample watchdog directive is shown below:
watchdog /dev/watchdog
The most common watchdog device currently used with general Linux
systems is the softdog device. The softdog device is a
software-based watchdog device and is usually referred to as
/dev/watchdog - although like most UNIX devices, this is a
convention not a rule.
This functionality has been replaced by cluster self-monitoring and
STONITH resource agents in Pacemaker. This directive should no
longer be used.

REQUIREDDIRECTIVES

The following directives must always be present in ha.cf:
o At least one communication topology directive (bcast, mcast, or
ucast);
o Either one or more node directives, or autojoinany.